Transalkylation of certain poly-tert-butylphenols



United States Patent "w 3,418,380

Patented Dec. 24, 1968 3418 380 2- and 6-positions, that is, ortho tothe hydroxyl. The butyl group in the 4-or para-position in the moststable IN and requires debutylating conditions to dislodge it. In

Robert L Laufer and Men.0 D. Kulik, Pittsburgh, Pa prior work, thecatalytic transalkylation of butylated signors, by mesne assignments, toConsolidation Coal 5 Pheho1s has resulted 1n the mlgl'atahle oftho'hhtylg p C a corporation of D l transferring principally to the 4- 0rpara-postion of the No Drawing. Filed July 28, 1965, Ser. No. 475,587phenol, thus increasing preferentially the amount of 4- 4 Claims. (Cl.260-624) butylphenol. By the practice of the present invention, the

transfer of tthe migratable groups to the ortho-position of the phenolis favored. However, it must be remembered ABSTRACT F THE DISCLOSUREthat the product will contain at least an equimolar The transbutylationof 2,4 di tert butylphenol and amount of a 4 butyl j hhhatituted PhehO1Since the butyl of 2,4,6 tri tert butylphenol in the presence of ung pIn the P 'P not afieeted y the eohdl' substituted phenol underconditions such that ortho-subtlohs 0f the reactionstitution rather thanpara-substitution of the unsubstituted 15 For a t r understandlng of ourlnventlon, lts obh l i b i d 180115 and advantages, reference should behad to the following examples:

This invention relates to the transalkylation of certain EXAMPLE 1 P 3tel't hutylphehols, and more particularly, to the Transalkylation of2,4-di-tert-butylphenol transalkylation of 2,4,6 tri tert butylphenoland 2,4- ditert butylphenol, separately or in admixture. The {eaetlehWas earned Q a 500 flask P Th butylphenols are generally f l either asvlded wlth a thermometer, stirrer, reflux condenser wlth antioxidantsfor oxygen sensitive organic compositions dfylhg tube and aheatlhgmafltle- The such as rubber and lubricating oils, or as intermediates yp n (939% P y) the Phenol -ti h a uf t f such antioxidants, AS might besynthetlc, redlstllled) were charged lnto the flask. As in expected,however, they differ sufficiently in their antit other examples, eam01111t 0f Phenol p y Was oxidant properties to make some in greaterdemand than 111 excess of that reqhlred t0 P P all the I others.Accordingly, it would be desirable to be able to Stituted butyl r p p eon the bqtylated p The convert one to the other as the need arose. It isrelativeexact amount 15 glveh 1n the Cemposltioh of the feed in 1 i l tod b l groups i ll bl f hi both Table I below. The flask contents werestirred and heated as to number and location. However, the converse isnot to 2 A Sample of about 1111. s drawn Wlth necessarily true. Forexample, it has not hitherto been a Pipette for gas Chromatographyahalysls pl 9- commercially feasible to convert poly-butyl'ated phenolsTable Theh, of 9598% slllhlrlc acld t th b hmd h L I particular, i hasnot been was added. The reaction was allowed to proceed at 90commercially feasible to convert either 2,4 di tertand a 05 1111- Sampleof the flask Contents Was taken butylphenol or 2,4,6 tri tertbutylphenol preferenintervals of time Shown in Table The Sample tiallyto 2 tert butylphenol, that is, to 2 tert butylwas neutralized with asmall amount of moist NaHCO phenol rather than to l-tert-butylphenol.and analyzed by gas chromatography for product dis- In accordance withour invention, we have provided 40 tribution. The distribution of theproducts in weight pera process for converting a tert-butylphenolselected from cent is shown in Table I.

TABLE I.-TRANSALKYLATION OF 2,4-DI TE RT-B UIYLPHENOL Sample Reaction 2+4-t- 2,6-di-t- 2,4-di-t- 2,4,6-tri-t- N o. Lune, Phenol butylphenolbutylphenol butylphenol butylphenol butylphenol ours 1 (feed) 0. 0 50. 40. 0 0. 2 0. 3 49. 1 0 0 51:11:11: 510 are "9'? "if "'i} 'i the classconsisting of 2,4-di-tert-butylphenol, 2,4,6-tri- 50 EXAMPLE 2tert-butylphenol, and mixtures thereof to 2 tert butylphenol. Theprocess comprises reacting the selected tert- Transalkylatlon of2464rhtert'buty1phen0l butylphenol with phenol itself at a temperaturebetween The apparatus used was the same described in the 75 and 150 C.in the presence of a small amount of preceding experiment. The 2,4,6 tritert-butylphenol concentrated sulfuric acid. The amount of sulfuric acid(99.2% purity) and the phenol (U.S.P. synthetic, redispresent must besmall, less than 0.5 percent by weight of ll d) W r Charged into theflask. The flask contents the selected butylphenol or butylphenols, asthe case may Were stirred and heated to 90 C. and 0.26 gm. of conbe. Ifthis amount is exceeded, then 4-tert-butylphenol is centrated (9698%) H80 was added from a syringe.

produced in preference to the desired Z-tert-butylphenol. Samples weretaken at intervals of time and analyzed by In the catalytictransalkylation of either 2,4-di-tert-bugas chromatography. The productdistribution in weight tylphenol or 2,4,6 tri tert butylphenol in thepresence percent at the different intervals is shown in Table II ofphenol, the migratable butyl groups are those in the below:

TABLE II.T RANSALKYLATION OF 2,4,6-T RI-TE RT-B UTYLPHENOL SampleReaction 2-t- 4-t- 2,6-di-t- 2,4-di-t- 2,4,6-trit- No. Elma, Phenolbutylphenol butylphenol butylphenol butylphenol butylphenol ours I(feed) 0.0 46.6 0.0 0 0 0.0 0.4 53.0 0.5 36.7 9.9 3.0 1. O 22.5 26.9 1.5 31. 6 14. 8 3. 0 1. 7 36. 5 12. 4 3. 5 29. 4 l7. 1 4. 8 2. 0 42. 0 4.7 5.0 27.4 18.2 5.6 1.5 43.9 3.4

0 EXAMPLE 3 Transalkylation of mixtures of 2,4-di-tert-buty1phenol and2,4,6-tri-tert-buty1phenol A synthetic mixture of2,4-di-tert-butylphenol and 2,4, 6-tri-tert-butylphenol was reacted withphenol in a threeliter, 3-necked flask provided with a stirrer, refluxcondenser, thermometer, and drying tube. The composition of thesynthetic mixture is given below in Table III. The conditions andproduct distribution are given in Table IV.

TABLE III.-Composition of synthetic mixture Component: Percent by weigh2-tert-butylpheno1 0.0 4-tert-butylpheno1 0.2 2,6-di-tert-butylphenol2.7 2,4-di-tert-butylphenol 39.3 2,4,6-tri-tert-butylphenol 57.8 Highboilers 0.0

2,4-di-tert-buty1phenol 53.4 2,4,6-tri-tert-butylphenol 4.8

Based on charge of mixture of 2,4-ditert-butylphenol and2,4,(i-tri-te1't-butylpl1eno1 in the synthetic mixture.

According to the provisions of the patent statutes, we have explainedthe principle, preferred construction, and mode of operation of ourinvention and have illustrated and described what we now consider torepresent its best embodiment. However, we desire to have it understoodthat, within the scope of the appended claims, the invention may bepracticed otherwise than as specifically illustrated and described.

We claim:

1. A process for transalkylation of a poly-tert-butylphenol selectedfrom the class consisting of 2,4-di-tertbutylphenol and2,4,6-tritert-butylphenol which comprises heating saidpoly-tert-butylphenol with unsubstituted phenol at a temperature betweenand C. in

the presence of concentrated sulfuric acid, the amount of the sulfuricacid being less than 0.5 percent by weight of the selected butylphenolspresent, whereby said unsubstituted phenol is preferentially convertedto 2-tert-butylphenol.

2. A process according to claim 1 in which the selected butylphenol is2,4-di-tert-butylphenol.

3. A process according to claim 1 in which the selected butylphenol is2,4,6-tri-tert-butylphenol.

4. A process according to claim 1 in which the selected butylphenol is amixture of 2,4,6-tri-tert-butylpheno1 and 2,4-di-tert-butylphenol.

References Cited UNITED STATES PATENTS 1,972,599 9/1934 Perkins et a1260624 2,189,805 2/ 1940 Kyrides et al 260624 2,553,538 5/1957 Arnold260624 LEON ZITVER, Primary Examiner.

W. B. LONE, Assistant Examiner.

